Email submission failed in Laravel

Tried to send an email but receive the error below

Connection could not be established with host smtp.sendgrid.net :stream_socket_client(): unable to connect to tcp://smtp.sendgrid.net:587 (Connection refused)

I used sendgrid for email submission when failed to implement google smtp. But it appeared that the result is still the same where the error shown exactly the same.

This is my mail configuration from .env

MAIL_DRIVER=smtp
MAIL_HOST=smtp.sendgrid.net
MAIL_PORT=587
MAIL_USERNAME=sendgrid-username-here
MAIL_PASSWORD=sendgrid-password-here
MAIL_ENCRYPTION=tls

I saw a lot post discussing about the same error but all the solutions are not working for my side. Just an additional info, my website is running on live server and actually secured with ssl installed (in subdomain) but for some reason it get detected as not secure. I'm not sure if this can be one of the reason.

via Chebli Mohamed